Guardian: Both John McCain and Barack Obama tout their green credentials on the campaign trail, but today their frequent absences from Congress doomed them to abysmal ratings on a leading US environmental group’s annual scorecard. The League of Conservation Voters has ranked the environmental commitment of members of Congress for 37 years on its annual scorecards, which tally votes that legislators take on green issues. Missed votes detract from one’s score, however, which proved bad news for …